[vsnet-grb-info 22794] GRB 190627A: Montarrenti Observatory optical detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  24893
SUBJECT: GRB 190627A: Montarrenti Observatory optical detection
DATE:    19/06/27 23:30:48 GMT
FROM:    Simone Leonini at Monarrenti Obs  <s.leonini at iol.it>

S. Leonini, M. Conti and P. Rosi (Montarrenti Observatory, Siena, Italy) report:

We observed the optical afterglow of GRB 190627A (Swift trigger 911609, E. Sonbas et al., GCN Circ. 24888) with the automatic 0.53m RC telescope + U47 detector at Montarrenti Observatory (Siena, Italy, IAU code C88).

The observations were started immediately after the sunset (approximately 9 hours post-burst) stacking 3 unfiltered CCD exposures of 30s for each run.

The OT was detected in all frames as follows:

2019 Jun 27.85897 UT (20:36:55 mid-time) R=18.0 +/-0.14
2019 Jun 27.92990 UT (22:19:03 mid-time) R=18.1 +/-0.13

Preliminary magnitudes were obtained using Astrometrica software using USNO-B1 catalogue for positions and photometry. An ensemble between 121 and 126 stars were used for the magnitude comparison. Measures are not corrected for galactic dust extinction.

The position of the GRB (within the error box given by Swift) is the following:

RA    (J2000.0) 16h 19m 18.70s +/-0.19
Decl. (J2000.0) -05° 17'  20.8"   +/-0.18

The message may be cited.